I get the feelilng I'm running original tires. But yes they are correct. They even keep air despite being rotted. When I start it always turns on the ICE. Then after a minute or 30s it shuts off and goes into EV. Battery has not gone below 45% soc.

If the PTU is completely done it might make sense to disconnect it and take down the d/s. But right now I don't know where the gunk came from. It was on the bottom of the PTU and not around where it connects to the center shaft. Could be the joint between it and the trans but that area doesn't look super dirty either. Wish there was a stopleak for this as I don't want to take the whole thing out for just a seal. No noises like one would expect with a toasted PTU. No new gunk returned when I sprayed brake cleaner.

So what is a good way to suck out the fluid when I go change it? The video on the PTU service recommended some $60 brake pressure bleeder which makes no sense.

Something like this: ??

That's what's holding me up as to seeing what's in there as nothing is available locally to suck it out.

 

> Then after a minute or 30s it shuts off and goes into EV. Battery has not gone below 45% soc.

Eventually when the battery is fully conditioned and the temperature is correct it should *start* in EV and then do almost the exact opposite and spin up the ICE after some time with the key in RUN. It sounds like you're not there yet, but it's hard to tell because it depends intimately on temperature, etc.

The tires are probably original or maybe 1X replaced. The Michelin Latitudes on my car with ~60k miles were original, hard, stiff, about 2/3rds worn out and were visibly dry rotted. Terrible in the rain, but they held air. I replaced them with Pirelli Scorpion Verde A/S Plus IIs that I somehow found on a Walmart website at a Crazy Eddie "insane" price of $116 each with free shipping. They're now $145 from the same Walmart (after I posted it here!!) and also on TireRack. I like 'em. YMMV. Lots of people have favorite tires for all kinds of reasons. The Pirellis were awesome and very precise and surefooted yesterday at 90-95 MPH with a Mercedes 4MATIC SUV driven by a slick-looking dude with vanity plates, including through some smooth highway sweeping corners. We weren't racing, just driving quickly under prevailing conditions and I was impressed by the Pirelli tracking and road holding. No slop from steering input to direction change. I never felt the "creepy-creeps" of impending doom or that I was pushing the car too hard.

You may not have a seal leak. It may be the vent bolt!

Link 1: There was a TSB: PTU VENT BOLT LEAK - MISDIAGNOSED AS PTU
SHAFT SEAL LEAK

Link2: FTM's video on a PTU with only a fill plug showing his suction device, which is comparatively expensive. He links to a relatively cheap device that sells for $32.24 on Amazon and doesn't require an air compressor. Your ~$12 option is basically a big turkey baster with a hose. It will probably work, but you will have to work a little harder. You may also need a longer and more flexible hose to attach, but you can get clear PVC hose cheaply that should fit on there. Then you can clean it and pump the fluid back in, so on a budget I would try your setup. Even if it is just the first link problem, you are going to want to change this fluid, and at least you will know that the seals are probably OK and you don't have something more evil to contend with.


"Patience is key here." There is no drain plug as far as I know, on these FEH units. You have to improvise and it's kind of slow and emotionally intense episode of: "As The Fluid Changes." If you have a GF/SO who is nice enough to bring you a beer or two on a weekend while you work and say calm and soothing things, that will help.

 

Not that it really matters, but one can answer the tire age question:

Four digit DOT code on the tire gives YYWW (year and week) of manufacture. Compare to manufacture date of the VIN.

 

I'll have to look at the date codes... it has michelins except for 1. I went for a good long drive and there is definitely some kind of driveline noise. Maybe I should record and post it. Kinda sounds like a CV axle but I dunno. The D/S is pretty rusted so the U joints are lookin not so great. I saw others who removed theirs so if my PTU is failed it should probably "fix it" as spinning with no load would let it run for a long time.

This is what BSG dude links to: as his "inexpensive suction device" It is not a suction device at all but returns

ARES 18007-12-Piece Master Cylinder Adapter Set - Included Adapters Work on Most Current Master Cylinder Reservoirs - for Brake Fluid Bleeding

what does it show for you? I got a brake bleeder last time.

21.7mpg now and +7.03 long term fuel. Sometimes it goes down to 6.5 and then back up. Maybe something else is still up. What are you all seeing on your cars in terms of LT FT. Torque is telling me 32-38mpg and 26 with A/C on. Probably not super accurate unless you drive with it for multiple trips.

Dunno if putting it on 4 jackstands and looking at the driveline would be a good idea. Probably easier than trying to deduce what's wrong by sound alone. I don't even know if my d/s spins.

 

Yeah, his second link is not working reliably. I get different results today also, a kit for working on master cylinders. He's using abbreviated/synthetic TinyURLs with the ".to" top level domain - that's Tonga, the 750 total square mile archipelago of islands in the south Pacific - and they are getting redirected by YouTube/Amazon, so it's hard to say what he meant to link to. That's a pain. Someone should alert him to the fact that maybe those abbreviated Amazon links are not permanent. He supposedly earns an affiliate fee from the sales if people click the links, so if they become invalid, he's losing money. I wouldn't be surprised if Amazon and YouTube do that stuff deliberately so Jeff Bezos can afford to put a jacuzzi and a sauna in his new jet plane and he and his new girlfriends can relax in style on a long flight. I'll send him an email.

Sounds like a good idea to me esp. with a helper and nice sturdy jackstands on a strong surface. By the way the power is transmitted through the 4WD by a clutch that is driven on a pulse-width modulated duty cycle under the control of the 4x4 Control Module.

If you have a good ear you'll hear grinding if it is there and maybe be able to localize it. Have a stethoscope, Dr.?

These two piece driveshaft units appear to use a center support bearing of some kind where the halves join up. Those can obviously go bad also.

It's good to see the mileage improvements, you're moving in the right direction pretty fast.

 

Yes, sorry. The relevant Ford specification is VC-7-B / WSS-M97B51-A1. Zerex G-05 meets the spec. and might be easier to find.

 

Engine oil is changed. At a loss with this suspension. I jacked up each side of the car. There is play in the PTU but not much. So it's not completely messed up. Strange clicking in the CV shafts. Not sure if it's just angle and plastic or if they are the cause of the hum. I heard it from both sides (pass worst) and touched the upper boot and felt some vibration. It sounds a little plasticky or rubbery. I was expecting wheel bearings and was looking how to replace them but they seem solid.

One video of the clicking: https://imgur.com/a/oYNj0bE
2nd video of the clicking : https://imgur.com/a/ZbpTxwk

PTU pics: https://imgur.com/a/Pq9iLyc
That plastic bushing on the pass side spins freely. If it was only that seal it's doable.


You've got to come original.

 

I'll take a look/listen in a few mins. Those tires are tired. Your Michelin Man is starting to look like The Thing. When the cartoon mascots start to look like each other, the days for those tires are numbered.

The Thing Says: "Cracks Great for Superheros! Not so Much for Tires."

Michelin Man says: Don't Crack Me Up!

 

It sounds like this guy's video. Most people have other issues but I guess I can go drive in circles in a parking lot and see if it does it too.

 

It looks and sounds to me like those CV joints are dry and worn. They will not get less dry and/or worn by themselves. They may NOT be completely worn out, but they definitely sound dry and they're clicking as the ***** try to make their way around inside the cage. Unless something else is making contact somewhere we can't see, you are not hearing "plastic click." You are hearing the ball bearings in the joint clicking and sticking inside the joints and inside the boot(s). If you take the halfshafts out you could plausibly disassemble, totally clean and repack one side and see if the wear isn't too bad and it quiets down. Once you get it apart you'll be able to inspect the races inside and see whether there's a lot of damage. The problem with CV joints is that they can go for a long time making noises of various kinds, and then they just go ---===<<<BANG>>>===--- one day, usually in a corner or when the suspension is working hard, and it's the last noise you hear before a lot more grief happens. I lost a rear halfshaft on an Audi Quattro (an '86 4000CS similar to this one, which was a fantastic car) this way and mayhem took place.


1987 Audi 4000 CS Quattro 5SP. Really an incredible car, especially in the snow with Nokian Hakkapelittas. Almost unstoppable if the CV joints were good. I wish they still made this car with a new engine and accessories but the same chassis. It was almost perfect.

I haven't done anything like this in a long time. It's in the service manual I've linked to, you begin by removing the springs (yeah, those springs) it's going to take time.

You may be able to take off the clamps, slide the boot back or cut it off, clean the whole thing out and then get in there and repack them with good CV joint grease and put on one of those "halfway sealed" boots, but it's kind of a crapshoot. It's pretty labor intensive, and if the joints are dry there is a reason. These things are supposed to be totally smooth and slide around through their full range without resistance or any noise, and without much wear inside. Try to listen closely and figure out whether the clicking is coming from the outers or inners.

It definitely sounds to me like they're worn and dried inside. You'll have to judge what to do based on cost and what you discover, but untreated they will go BANG after a while and then you're in uncharted waters. I do not know what the complete 4WD rear halfshafts cost with both joints.

Don't take my word for it, hopefully someone else can confirm, but it sounds to me like those CV joints are dry and possibly lost.

HTH, sad to say.